Display device

ABSTRACT

A display portion of a display device includes a gate wiring formed of a first metal layer, a signal line formed of a second metal layer, a metal wiring formed of a third metal layer. A terminal portion of the display device includes a first metal portion formed of the second metal layer, and a second metal portion that is laminated on the first metal portion and formed of the third metal layer. The second metal portion covers an upper surface and a side surface of the first metal portion, and a peripheral portion of the second metal portion is covered by an organic insulating film, and the inside of the peripheral portion of the second metal portion is exposed via a first through hole formed in the organic insulating film.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Bypass Continuation Application of PCTinternational Application No. PCT/JP2019/017168 filed on Apr. 23, 2019,which claims priority to Japanese Patent Application No. 2018-086367,filed on Apr. 27, 2018, the entire contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to display devices, and particularly, thepresent invention can be applied to a display device including aterminal portion and an inspection pad for being connected to a flexiblewiring substrate or a driver IC.

A display device using liquid crystal, organic electroluminescence, orthe like is usually equipped with a terminal portion and an inspectionpad, for example, at an edge of the substrate of the display panel ofthe display device. The terminal portion includes, for example, pluralconnection terminals such as a terminal to which video signals areprovided, a terminal to which a clock signal is provided, and a terminalto which electric power is provided in order to display images on thedisplay panel. The terminal portion of the display panel is connected toa flexible wiring substrate (also referred to as an FPC substrate or aflexible printed circuit substrate hereinafter) and a driver IC via ananisotropic conductive film (also referred to as an ACF film). Forexample, Japanese Unexamined Patent Application Publication No.2017-151371 proposes the configurations of the respective terminals of aterminal portion.

SUMMARY OF THE INVENTION

In order to verify the reliability of a display device, the inventors ofthe present invention conducted a burn-in test of the display device insuch a way that the display device is made to operate under a hightemperature and high humidity environment by supplying electric power tothe display device. AS a result of this verification, the inventors havefound that there is a case where a terminal of the terminal portion ofthe display device, to which the electric power is supplied, is erodedowing to a certain configuration of the terminal portion.

An object of the present invention is to provide a display device thatcan be expected to improve the reliability of the terminal portion ofthe display device itself.

Problems other than the above and new features will be explicitly shownby the descriptions of this specification and the accompanying drawings.

The outline of a typical aspect of the present invention will be brieflyexplained as follows.

To put it concretely, a display device includes: a display panel havinga display portion and a mounting unit, and a terminal portion in themounting unit. The display portion includes: a gate wiring formed of afirst metal layer; a signal line formed of a second metal layer; a metalwiring formed of a third metal layer; a first transparent electrodeformed of a first transparent conductive film, and a second transparentelectrode formed of a second transparent conductive film. The terminalportion includes: a first metal portion formed of the second metallayer; and a second metal portion that is laminated on the first metalportion and formed of the third metal layer. The second metal portioncovers an upper surface and a side surface of the first metal portion,and a peripheral portion of the second metal portion is covered by anorganic insulating film, and the inside of the peripheral portion of thesecond metal portion is exposed via a first through hole formed in theorganic insulating film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing the exterior appearance of a displaydevice DSP according to this embodiment;

FIG. 2 is a plan view showing a configuration example of a touch sensorTS;

FIG. 3 is a diagram showing a fundamental configuration and anequivalent circuit of a pixel PX;

FIG. 4 is a plan view showing an example of a pixel layout;

FIG. 5 is a cross-sectional view of a first substrate SUB1 taken alongthe line A-B shown in FIG. 4 ;

FIG. 6 is a cross-sectional view of a display panel PNL taken along theline C-D shown in FIG. 4 ;

FIG. 7 is a perspective view schematically showing the display deviceDSP shown in FIG. 1 ;

FIG. 8 is a plan view showing a configuration example of a mounting uniton the first substrate SUB1;

FIG. 9 is a cross-sectional view of the mounting unit MA and a flexibleprinted circuit substrate 1 taken along the line E-E′ shown in FIG. 7 ;

FIG. 10 is a plan view for explaining a terminal portion according to acomparative example;

FIG. 11 is a cross-sectional view of the terminal portion taken alongthe line F-F′ shown in FIG. 10 ;

FIG. 12 is a cross-sectional view of the terminal portion according tothe comparative example in the middle of manufacturing;

FIG. 13 is a plan view showing a terminal portion T1 according to theembodiment;

FIG. 14 is a cross-sectional view of the terminal portion T1 taken alongthe line G-G′ shown in FIG. 13 ;

FIG. 15 is a cross-sectional view of the terminal portion T1 taken alongthe line H-H′ shown in FIG. 13 ;

FIG. 16 is a cross-sectional view of the terminal portion T1 taken alongthe line I-I′ shown in FIG. 13 ;

FIG. 17 is an enlarged view conceptually showing the terminal portion T1shown in FIG. 13 and conductive beads CP in an anisotropic conductivefilm ACF;

FIG. 18 is a plan view of a terminal portion T3 according to theembodiment;

FIG. 19 is a plan view of a terminal portion T1 according to amodification 1;

FIG. 20 is a cross-sectional view of the terminal portion T1 taken alongthe line J-J′ shown in FIG. 19 ;

FIG. 21 is a plan view of a terminal portion T1 according to amodification 2; and

FIG. 22 is a cross-sectional view of the terminal portion T1 taken alongthe line K-K′ shown in FIG. 21 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, an embodiment of the present invention will be explainedwith reference to the accompanying drawings.

Here, the following disclosure is only an example, and it goes withoutsaying that various modifications that may be made accordingly by thoseskilled in the art without deviating from the gist of the presentinvention fall within the scope of the present invention. In addition,there are some cases where, in the accompanying drawings, the widths,thicknesses, shapes, and the like of respective portions of theembodiment are schematically depicted differently from what they reallyare, but these depictions are only examples, so that the interpretationof the present invention is not limited to these depictions.

Furthermore, in this specification and the accompanying drawings, thesame components as components that have appeared in already-describeddrawings are given the same reference signs, and detailed explanationsabout them may be omitted accordingly.

In this embodiment, a liquid crystal display device is disclosed as anexample of a display device. This liquid crystal device can be used forvarious kinds of devices such as a smart phone; a tablet terminal; acellular phone terminal; a personal computer; a TV receiver; anin-vehicle device; a game machine; and the like. Here, the mainconfigurations disclosed in this embodiment can be applied to aself-luminous type display device including organic electroluminescencedisplay elements and the like; an electronic paper type display deviceincluding electrophoretic elements and the like; a display device usingMEMS (Micro Electro Mechanical Systems); a display device usingelectrochromism; and the like.

(Entire Configuration Example of Display Device)

FIG. 1 is a plan view showing the exterior appearance of a displaydevice DSP according to this embodiment. Although a first direction X, asecond direction Y, and a third direction Z are perpendicular to oneanother in this example, it is also conceivable that these directionsintersect with one another at angles other than a right angle. The firstdirection X and the second direction Y are corresponding to directionsparallel with the main surface of a substrate included in the displaydevice DSP respectively, and the third direction Z is corresponding to adirection of the thickness of the display device DSP. In thisspecification, a direction from the origin of the XYZ coordinates to thetip of an arrow showing the third direction Z is referred to as anupward direction (or an up direction for simplicity) and a directionfrom the tip of the arrow to the origin of the XYZ coordinates isrereferred to as a downward direction (or a down direction forsimplicity). In addition, it will be assumed that there is anobservation point for observing the display device DSP to the tip sideof the arrow showing the third direction Z, and viewing an object fromthis observation point to an XY plane defined by the first direction Xand the second direction Y is referred to as viewing the object in aplanar view.

In FIG. 1 , the plan view of the display device DSP on the XY plane isshown. The display device DSP includes: a display panel PNL; a flexibleprinted circuit substrate (flexible wiring substrate) 1; an IC chip 2;and a circuit substrate 3.

The display panel PNL is a liquid crystal display panel and includes: afirst substrate SUB1; a second substrate SUB2; an after-mentioned liquidcrystal layer LC; a seal SE; a light shielding layer LS; and spacers SP1to SP4. Furthermore, the display panel PNL includes a display portion(display area) DA for displaying images and a frame shaped nondisplayportion (nondisplay area) NDA surrounding the display portion DA. Thesecond substrate SUB2 faces the first substrate SUB1. The firstsubstrate SUB1 includes a mounting unit MA extending further in thesecond direction Y than the second substrate SUB2.

The seal SE is located in the nondisplay portion NDA and bonds the firstsubstrate SUB1 and the second substrate SUB2 together, and the seal SEseals the liquid crystal layer LC. The light shielding layer LS islocated in the nondisplay portion NDA. The seal SE is formed at an areawhere the seal SE overlaps the light shielding layer LS in a planarview. In FIG. 1 , an area where the seal SE is disposed and an areawhere the light shielding layer LS is disposed are illustrated bydifferent kinds of hatched lines respectively, and an area where theseal SE and the light shielding layer LS overlap each other isillustrated by cross-hatching. The light shielding layer LS is formed onthe second substrate SUB2.

Each of the spacers SP1 to SP4 is located in the nondisplay portion NDA.The spacer SP1 is located in the outermost peripheral of the displaypanel PNL. The spacer SP2 is located nearer to the display portion DAthan the spacer SP1. The spacer SP1 and the spacer SP2 overlap the sealSE. The spacer SP3 and the spacer SP4 are located nearer to the displayportion DA than the seal SE. The spacers SP1 to SP4 are formed on thesecond substrate SUB2 in this case, but it is conceivable that thespacers SP1 to SP4 are formed on the first substrate SUB1.

The display portion DA is disposed inside an area surrounded by thelight shielding layer LS. The display portion DA includes plural pixelsdisposed in a matrix shape in the first direction X and in the seconddirection Y. The display portion DA includes: a pair of sides E1 and E2extending in the first direction X; a pair of sides E3 and E4 extendingin the second direction Y; and four round portions R1 to R4. The displaypanel PNL includes: a pair of sides E11 and E12 extending in the firstdirection X; a pair of sides E13 and E14 extending in the seconddirection Y; and four round portions R11 to R14. The round portions R11to R14 are located outside the round portions R1 to R4 respectively. Thecurvature radius of the round portion R11 can be equal to that of theround portion R1 or can be different from that of the round portion R1.

The flexible printed circuit substrate 1 is mounted on the mounting unitMA and connected to the circuit substrate 3. IC chip 2 is mounted on theflexible printed circuit substrate 1. Here, it is also conceivable thatthe IC chip 2 is mounted on the mounting unit MA. The IC chip 2 embeds adisplay driver DD that outputs signals necessary for image display in adisplay mode in which images are displayed. In addition, in the exampleshown in FIG. 1 , the IC chip 2 embeds a touch controller TC forcontrolling a touch-sensing mode in which an object approaching ortouching the display device DSP is detected. In FIG. 1 , the IC chip 2is depicted by alternate long and short dashed lines, and the displaydriver DD and the touch controller TC are depicted by dotted lines.

The display panel PNL according to this embodiment can be any of atransmissive type panel having a transmissive display function thatdisplays images by selectively transmitting light emitted from the rearside of the first substrate SUB1, a reflective type panel having areflective display function that displays images by selectivelyreflecting light emitted from the front side of the second substrateSUB2, and a semi-transmissive type panel having both transmissivedisplay function and reflective display function.

In addition, although the detailed configuration of the display pane PNLis not explained here, it is conceivable that the display panel PNLincludes a configuration compatible with any of a display mode using alateral electric field along a main substrate surface, a display modeusing a longitudinal electric field along the normal line of the mainsubstrate surface, a display mode using an oblique electric field thatis oblique to the main substrate surface, and a display mode using anadequate combination of the abovementioned lateral, longitudinal, andoblique electric fields. Here, the main substrate surface is a surfaceparallel with the XY plan defined by the first direction X and thesecond direction Y. FIG. 2 is a plan view showing a configurationexample of a touch sensor TS. Although the touch sensor TS will beexplained as a self-capacity type touch sensor hereinafter, the touchsensor TS can be a mutual capacity type touch sensor. The touch sensorTS includes plural sensor electrodes Rx (Rx1, Rx2, . . . ) and pluralsensor wirings L (L1, L2, . . . ). The plural sensor electrodes Rx arelocated in the display portion DA, and disposed in a matrix shape in thefirst direction X and in the second direction Y. One sensor electrode Rxcomposes one sensor block B. The sensor block B is a minimum unitcapable of conducting touch sensing. The plural sensor wirings L areextending in the second direction Y respectively and arranged inparallel with one another in the first direction X in the displayportion DA. Each of the sensor wirings L is formed at a position whereeach of the sensor wirings overlap one of later-mentioned signal linesS. Furthermore, each of the sensor wirings L is pulled out to thenondisplay portion NDA and electrically connected to the IC chip 2 viathe flexible printed circuit substrate 1.

Here, attention is given to the relation among the sensor wirings L1 toL3 that are arranged in parallel with one another in the first directionX and the sensor electrodes Rx1 to Rx3 that are arranged in parallelwith one another in the second direction Y. The sensor wiring L1overlaps the sensor electrodes Rx1 to Rx3 and is electrically connectedto the sensor electrode Rx1.

The sensor wiring L2 overlaps the sensor electrodes Rx2 and Rx3 and iselectrically connected to the sensor electrode Rx2. A dummy wiring D20is spaced from the sensor wiring L2. The dummy wiring D20 overlaps thesensor electrode Rx1 and is electrically connected to the sensorelectrode Rx1. The sensor wiring L2 and the dummy wiring D20 are locatedon the same signal line.

The sensor wiring L3 overlaps the sensor electrode Rx3 and iselectrically connected to the sensor electrode Rx3. A dummy wiring D31overlaps the sensor electrode Rx1 and is electrically connected to thesensor electrode Rx1. A dummy wiring D32 is spaced from the dummy wiringD31 and the sensor wiring L3. The dummy wiring D32 overlaps the sensorelectrode Rx2 and is electrically connected to the sensor electrode Rx2.The sensor wiring L3, the dummy wirings D31 and D32 are located on thesame signal line.

In the touch sensing mode, the touch controller TC applies tough drivevoltages to the sensor wirings L. With this, the touch drive voltagesare applied to the sensor electrodes Rx, and sensing is conducted usingthe sensor electrodes Rx. Sensor signals corresponding to sensingresults obtained by using the sensor electrodes Rx are output to thetouch controller TC via the sensor wirings L. The touch controller TC oran external host processor detects whether or not there is an objectthat approaches or touches the display device DSP and the coordinates ofthe location of the object on the basis of the sensor signals.

In addition, in a display mode, sensor electrodes Rx function as commonelectrodes CE to which common voltages Vcom are applied. The commonvoltages are supplied, for example, from a voltage supply unit includedin the display driver DD via the sensor wirings L.

(Configuration Example of Pixel)

FIG. 3 is a diagram showing the basic configuration and an equivalentcircuit of a pixel PX. Plural scanning lines (scanning signal lines) G1,G2, are connected to a scanning line drive circuit GD. Plural signallines (video signal lines) S1, S2, are connected to a signal line drivecircuit SD. Here, it is not always necessary that the scanning lines Gand the signal lines S are linearly extending, and it is all right ifparts of these lines are bent. For example, even if parts of the signallines S are bent, it will be assumed that the signal lines S areextending in the second direction Y.

The one common electrode CE is connected to the voltage supply unit CDthat supplies the common voltages Vcom, and the one common electrode CEis disposed for plural pixels PX. Furthermore, each of the commonelectrodes CE is also connected to the touch controller TC and functionsas a sensor electrode RX. For example, 60 to 70 main pixels are disposedalong the first direction X and 60 to 70 main pixels are disposed alongthe second direction Y in one sensor block B. Here, one pixel PX is aminimum unit that can be controlled in accordance with pixel signals andsometimes referred to as a subpixel. In addition, there are some caseswhere a minimum unit for realizing color display is referred to as amain pixel. A main pixel is composed of plural subpixels PX thatrespectively display different colors. As an example, a main pixelincludes a red pixel for displaying red color, a green pixel fordisplaying green color, and a blue pixel for displaying blue color.Furthermore, it is also conceivable that the main pixel further incudesa white pixel for displaying white color.

Each pixel PX includes: a switching element SW; a pixel electrode PE; acommon electrode CE; a liquid crystal layer LC; and the like. Theswitching element SW is composed of, for example, a thin film transistor(TFT) and electrically connected to a scanning line G and a signal lineS. The scanning line G is connected to the switching element SW of eachof pixels PX arranged in parallel with one another in the firstdirection X. The signal line S is connected to the switching element SWof each of pixels arranged in parallel with one another in the seconddirection Y. The pixel electrode PE is electrically connected to theswitching element SW. The pixel electrode PE faces the common electrodeCE, and the liquid crystal layer LC is driven by an electric fieldinduced between the pixel electrode PE and the common electrode CE. Aretention capacitor CS is formed, for example, between an electrodehaving the same potential as the common electrode CE and an electrodehaving the same potential as the pixel electrode PE.

FIG. 4 is a plan view showing an example of a pixel layout. The mainportion of the pixel layout will be explained while attention is beingpaid to a pixel PX1 connected to a scanning line G2 and a signal lineS6. In FIG. 4 , a pixel PX2 is a pixel disposed under the pixel PX1, anda pixel electrode PE21 is the pixel electrode of the pixel PX2.

The switching element SW is electrically connected to the scanning lineG2 and the signal line S6. The switching element SW shown as an examplein FIG. 4 has a double gate structure. The switching element SW includesa semiconductor layer SC and a drain electrode DE. Here, in theswitching element SW, there are some cases where the drain electrode DEis referred to as a source electrode. The semiconductor layer SC isdisposed so that one part of the semiconductor layer SC overlaps thesignal line S6 and the other part extends between the signal lines S5and S6, and the semiconductor layer SC is formed in an approximate Ushape as a whole. The semiconductor layer SC intersects with thescanning line G2 both in an area where the semiconductor layer SCoverlaps the signal line S6 and in an area between a signal line S5 andthe signal line S6. The above two areas where the scanning line G2overlaps the semiconductor layer SC in the scanning line G2 function asgate electrodes GE1 and GE2 respectively. One edge SCA of thesemiconductor layer SC is electrically connected to the signal line S6via a contact hole CH1, and the other edge SCB of the semiconductorlayer SC is electrically connected to the drain electrode DE via acontact hole CH2. The drain electrode DE is formed in an island shapeand disposed between the single lines S5 and S6.

A pixel electrode PE11 includes plural charging poles Pal and one baseBS. The base overlaps the drain electrode DE. In addition, the base iselectrically connected to the electrode DE.

(Configuration Example of Cross-Section of Display Device)

FIG. 5 is a cross-sectional view of the first substrate SUB1 taken alongthe line A-B shown in FIG. 4 .

The first substrate SUB1 includes: an insulating substrate 10;insulating films 11 to 16; the semiconductor layer SC; the scanning line(first metal wiring) G2 formed of a first metal layer; the signal line(second metal wiring) S6 formed of a second metal layer; a metal wiring(third metal wiring) ML6 formed of a third metal layer; the commonelectrode (first transparent electrode) CE formed of a first transparentconductive film; the pixel electrode (second transparent electrode) PE;an orientation film AL1; and the like. Here, the pixel electrode (secondtransparent electrode) PE will be explained using after-mentioned FIG. 6.

The insulating substrate 10 is a light transmitting substrate such as aglass substrate or a flexible resin substrate. The insulating film 11 islocated on the insulating substrate 10. The semiconductor layer SC islocated on the insulating film 11 that is an undercoat film and coveredby the insulating film 12 that is a gate insulating film. Thesemiconductor layer SC is formed of, for example, polycrystallinesilicon, but it is also conceivable that the semiconductor layer SC isformed of amorphous silicon or oxide semiconductor.

The gate electrode GE1, which is a part of the scanning line G2, islocated on the insulating film 12 and covered by the insulating film(inorganic insulating film) 13. Here, other not-shown scanning lines arealso located in the same layer as the scanning line G2. It isconceivable that the scanning line G2 is formed of a metal material suchas aluminum (Al); titanium (Ti); silver (Ag); molybdenum (Mo); tungsten(W); cupper (Cu); chromium (Cr) or an alloy formed of a combination ofsome of the these metal materials, and it is all right if the scanningline G2 has either a monolayer structure or a multilayer structure. Asan example, the scanning line G2 is formed of a molybdenum-tungstenalloy.

The signal line S6 is located on the insulating film 13 and covered bythe insulating film (first organic insulating film) 14. Here, anothernot-shown signal line S2 is located in the same layer as the signal lineS6. It is conceivable that the signal line S6 is formed of any of theabovementioned metal materials or an alloy formed of a combination ofsome of the abovementioned metal materials, and it is all right if thesignal line S6 has either a monolayer structure or a multilayerstructure. As an example, the signal line S6 is a laminated body formedby laminating a first layer L11 including titanium (Ti), a second layerL12 including aluminum (Al), and a third layer L13 including titanium(Ti) in this order. The signal line S6 is in contact with thesemiconductor layer SC via the contact hole CH1 penetrating theinsulating films 12 and 13.

The metal wiring ML6 is located on the insulating film 14 and covered bythe insulating film (second organic insulating film) 15. It isconceivable that the metal wiring ML16 is formed of any of theabovementioned metal materials or alloy formed of a combination of someof the abovementioned metal materials, and it is all right if the metalwiring ML6 has either a monolayer structure or a multilayer structure.As an example, the metal wiring ML6 is a laminated body formed bylaminating a fourth layer L21 including molybdenum (Mo), a fifth layerL22 including aluminum (Al), and a sixth layer L23 including molybdenum(Mo) in this order. Here, it is also conceivable that the metal wiringML6 is a laminated body formed by laminating the fourth layer L21including titanium (Ti), the fifth layer L22 including aluminum (Al),and the sixth layer L23 including titanium (Ti) in this order.

The common electrode CE is located on the insulating film 15 and coveredby the insulating film (inorganic insulating film) 16. The commonelectrode CE is a transparent electrode (transparent conductive film)formed of a transparent conductive material such as indium tin oxide(ITO) or indium zinc oxide (IZO). The common electrode CE is in contactwith the metal wiring ML6 via the contact hole CH3 penetrating theinsulating film 15. The orientation film AL1 is located on theinsulating film 16.

It is conceivable that each of the insulating films 11 to 13 and theinsulating film 16 is an inorganic insulating film formed of aninorganic insulating material such as silicon oxide, silicon nitride, orsilicon nitride oxide, and it is all right if each of these insulatingfilms has either a monolayer structure or a multilayer structure. Theinsulating films 14 and 15 are organic insulating films formed of, forexample, an organic insulating material such as acrylate resin. Here,the insulating film 15 can be an inorganic insulating film.

As mentioned above, the common electrode CE functions as a sensorelectrode Rx, and the metal wiring ML6 functions as a sensor wiring Lelectrically connected to the sensor electrode Rx.

FIG. 6 is a cross-sectional view of the display panel PNL taken alongthe line C-D shown in FIG. 4 . The example shown in FIG. 6 iscorresponding to an example to which an FFS (Fringe Field Switching)mode, one of modes using lateral electric fields, is applied.

In the first substrate SUB1, the signal lines S5 and S6 are located onthe insulating film 13 and covered by the insulating film 14. A metalwiring ML5 and the metal wiring ML6 are located just above the signallines S5 and S6 respectively. The pixel electrode PE11 is located on theinsulating film 16 and covered by the orientation film AL1. The pixelelectrode PE11 is a transparent electrode (transparent conductive film)formed of a transparent conductive material such as ITO or IZO.

The second substrate SUB2 includes: an insulating substrate 20; lightshielding layers BM; a color filter CFG; an overcoat layer OC; anorientation film AL2, and the like.

The insulating substrate 20 is a light transmitting substrate such as aglass substrate or a flexible resin substrate as is the case with theinsulating substrate 10. The light shielding layers BM and the colorfilter CFG are located at the side of the insulating substrate 20 facingthe first substrate SUB1. The color filter CFG is disposed at a positionfacing the pixel electrode (second transparent electrode) PE11 and apart of the color filter CFG overlaps the light shielding layers BM. Theovercoat layer OC covers the color filter CFG. The overcoat layer OC isformed of transparent resin. Other color filters CFR and CDB are alsolocated at positions facing the pixel electrodes PE respectively, andthese color filters are covered by the overcoat layer OC as is the casewith the color filter CFG. The orientation film AL2 covers the overcoatlayer OC. The orientation films AL1 and AL2 are formed, for example, ofmaterials each of which has a horizontal orientation property.

The abovementioned first substrates SUB1 and second SUB2 are disposed sothat the orientation film AL1 and the orientation film AL2 face eachother. Although not shown in FIG. 6 , a main spacer and a sub-spacer aredisposed between the first substrate SUB1 and the second substrate SUB2. The main spacer forms a predefined cell gap between the orientationfilm AL1 and the orientation film AL2. The size of the cell gap is, forexample, 2 to 5 μm. The first substrate SUB1 and the second substrateSUB2 are bonded together by a seal member under the condition that thepredefined cell gap is formed.

The liquid crystal layer LC is located between the first substrate SUB1and the second substrate SUB2 and held between the orientation film AL1and the orientation film AL2. The liquid crystal layer LC includesliquid crystal molecules LM. The liquid crystal layer LC is formed of apositive type liquid crystal material the dielectric anisotropy of whichis positive or a negative type liquid crystal material the dielectricanisotropy of which is negative.

An optical element OD1 including a polarizing plate PL1 is bonded to theinsulating substrate 10. An optical element OD2 including a polarizingplate PL2 is bonded to the insulating substrate 20. Here, it isconceivable that each of the optical element OD1 and the optical elementOD2 includes a phase difference plate, a dispersion layer, and anantireflection layer as needed.

In such a display panel, in an off-state where any electric field is notformed between the pixel electrode PE and the common electrode CE, theliquid crystal molecules LM are initially oriented in a predefineddirection between the orientation film AL1 and the orientation film AL2.In such an off-state, light irradiated from an illumination device IL tothe display panel PNL is absorbed by the optical elements OD1 and OD2,so that a dark display appears. On the other hand, in an on-state wherean electric field is formed between the pixel electrode PE and thecommon electrode CE, the liquid crystal molecules LM are oriented in adirection different from the initial orientation direction, and thisorientation direction is controlled by the electric field. In such anon-state, a part of light irradiated from the illumination device ILpenetrates the optical elements OD1 d OD2, so that a bright displayappears.

(Configuration Example of Mounting Unit)

FIG. 7 is a perspective view schematically showing the display deviceDSP shown in FIG. 1 . FIG. 8 is a plan view showing a configurationexample of the mounting unit on the first substrate SUB1. FIG. 9 is across-sectional view of the mounting unit MA and the flexible printedcircuit substrate 1 taken along the line E-E′ shown in FIG. 7 .

As shown in FIG. 7 , the display device DSP includes the display panelPNL, the flexible printed circuit substrate (flexible wiring substrate)1. As shown in FIG. 1 , the display panel PNL includes the firstsubstrate SUB1, the second substrate SUB2, the display portion DA, andthe nondisplay portion NDA. The illumination device IL, which functionsas, for example, a backlight device, is provided at the underside of thefirst substrate SUB1. The first substrate SUB1 includes the mountingunit MA.

The mounting unit MA includes plural terminal portions T disposed so asto be arranged in parallel with one another as illustratively shown inFIG. 8 . A wiring area WA formed adjacently to the mounting unit MAincludes wiring portions W connected to the plural terminal portions T.The plural terminal portions T includes rectangle-shaped terminalportions T1 and T2 and an approximately U-shaped terminal portion T3.The plural terminal portions include: a terminal to which video signalsare supplied; a terminal to which clock signals are supplied; a terminalto which electric power is supplied; terminals for inputting/outputtingtouch drive voltages and sensing results; and the like. Therectangle-shaped terminal portion T1 can be used as the terminal towhich video signals are supplied; the terminal to which clock signalsare supplied; the terminals for inputting/outputting touch drivevoltages and sensing results; or the like, and a large number ofterminal portions T1 can be formed in the mounting unit MA. Theapproximately U-shaped terminal portion T3 can be used as the terminalto which electric power is supplied, and in this case the impedance ofthe relevant electric power supply can be made low. The terminal portionT2 is a terminal portion to which no wiring portion W is connected, thatis, a terminal portion the potential of which is electrically floating.

The plural terminal portions T are connected to plural wiring terminalsformed at one end of the flexible printed circuit substrate 1. The ICchip 2 is formed on the flexible printed circuit substrate 1, and theinput/output signals of the IC chip 2 are received from or transmittedto the display panel PNL via the plural terminal portions T. Pluralwiring terminals formed at the other end of the flexible printed circuitsubstrate 1 are connected to plural wiring terminals formed on thecircuit substrate 3 and connected to, for example, the inputs/outputs ofa host processor formed on the circuit substrate 3.

The connections between the plural terminal portions T and plural wiringterminals TF of the flexible printed circuit substrate 1 are establishedusing an anisotropic conductive film ACF as shown in FIG. 9 . Theanisotropic conductive film ACF can also be considered to be ananisotropic conductive film or an anisotropic conductive material. Theanisotropic conductive film ACF is made of thermosetting resin in whichplural conductive particles CP (also referred to as plural conductivebeads hereinafter) are mixed, and electric conductions between theterminal portions T and wiring terminals TF are obtained owing to theplural conductive particles CP. The structure of a conductive particleCP is a spherical body the diameter of which is 3 to 5 micrometers andthat is formed by laminating a nickel layer, a gold-plated layer, and anoutermost insulating layer from inside to outside. In order to form theconnections between the terminal portions T and the wiring terminals TF,the anisotropic conductive film ACF is sandwiched between the terminalportions T and the wiring terminals TF and the insulating layers of someconductive particles CP are broken using thermocompression or the like.As a result, electrically conductive paths between the terminal portionsT and the wiring terminals TF are formed by the nickel layers andgold-plated layers of the above conductive particles CP. Becauseconductive particles CP in parts of the anisotropic conductive film ACFto which the thermocompression is not applied keep their insulatinglayers intact, insulations among the terminal portions T disposed inparallel with one another in the mounting unit MA are kept as they are.

(Comparison Example: Configuration of Terminal Portion)

Next, a comparison example will be explained with reference to FIG. 10to FIG. 12 . FIG. 10 is a plan view for explaining terminal portionsaccording to the comparison example. FIG. 11 shows a cross-sectionalview of a terminal portion taken along the line F-F′ shown in FIG. 10 .FIG. 12 is a cross-sectional view of the terminal portion according tothe comparative example in the middle of manufacturing. Here, thiscomparison example includes a configuration examined by the presentinventors, so that this comparison example is not a publicly known art.

FIG. 10 illustratively shows two terminal portions T10 and T11 disposedadjacently to each other in the mounting unit MA. The terminal portionT10 is a power terminal portion to which, for example, a first referencevoltage that is a low voltage such as the ground potential (GND) or 0 Vis supplied, and the terminal portion T11 is a power terminal portion towhich, for example, a second reference voltage that is a higher voltagethan the first reference voltage such as an electric power potential(Vdd) or 7 V is supplied.

There are some cases where a burn-in test is conducted on the displaydevice DSP having such terminal portions T10 and T11 under a hightemperature and high humidity environment in order to evaluate andverify the reliability of the display device DSP. Here, the hightemperature is 85° C. and the high humidity is 85% RH. The burn-in testis a test conducted on the display device DSP for a long time (forexample, 240 hours) under the operation condition that the same electricpower potentials as are used in the real operation of the display deviceDSP are supplied to the display device DSP. In other words, thelong-time test is conducted for a long time under the condition that theterminal portion T10 is supplied with the first reference voltage andthe terminal portion T11 is supplied with the second reference voltage.In such a burn-in test, there are some cases where corrosion COR isinduced at the side of the terminal portion T11 facing the terminalportion T10 as shown in FIG. 10 . It is conceivable that the corrosionCOR of the terminal portion T11 is induced because a lateral electricfield induced between the terminal portion T10 and the terminal portionT11 had an influence on moisture.

As shown in FIG. 11 , the terminal portion T11 includes: a conductivelayer Ta; a conductive layer Tb; a conductive layer Tc; and a conductivelayer Td. Here, the insulating film 14 and the insulating film 15 arenot disposed in an area where the terminal portions T (T10 and T11) aredisposed in the first substrate SUB1. Therefore, the insulating film 16is laminated on the insulating film 13. Here, although FIG. 11illustratively shows the cross-sectional view of the terminal portionT11, other plural terminal portions T disposed in the mounting unit MAshown in FIG. 8 also have similar cross-sectional views.

The conductive layer Ta is located on the insulating film 13. Theconductive layer Ta is located in the same layer as the signal line S6shown in FIG. 5 and formed of the same material as the signal line S6.

The conductive layer Tb is laminated on the conductive layer Ta and theinsulating film 13 and covers the conductive layer Ta. The conductivelayer Tb is located in the same layer as the metal wiring ML6 shown inFIG. 5 and formed of the same material as the metal wiring ML6.

The conductive layer Tc is laminated on the conductive layer Tb and theinsulating film 13 and covers the conductive layer Tb. The conductivelayer Tc is located in the same layer as the common electrode CE shownin FIG. 5 and formed of the same material as the common electrode CE.The conductive layer Tc and the insulating film 13 are covered by theinsulating film 16. The insulating film 16 includes a through bore thatpenetrates to the conductive layer Tc.

The conductive layer Td is located on the insulating film 16 andlaminated on the conductive layer Tc that is exposed via the throughbore formed in the insulating film 16. The conductive layer Td islocated in the same layer as the pixel electrode PE11 shown in FIG. 6and formed of the same material as the pixel electrode PE11.

Of the vicinities of the edges Tb1 and Tb2 of the conductive layer Tb,the vicinity of the edge Tb1 is enlarged and shown in FIG. 11 . Theconductive layer Tb is composed of a laminated body obtained bylaminating a fourth layer L21 including molybdic (Mo), a fifth layer L22including aluminum (Al), and a sixth layer L23 including molybdic (Mo)in this order, and it has become clear that the left edge of the fifthlayer L22 is located at a position righter than the left edges of thefourth layer L21 and the sixth layer L23. In other words, it has becomeclear that the edge of the fifth layer L22 is in a state of being boredand there is a gap (or a concave portion) GA between the conductivelayer Tc and the edge of the fifth layer L22. And it has become clearthat the insulating film 16 cannot sufficiently cover the conductivelayer Tc for the above reason, and moisture intrudes between theinsulating film 16 and the conductive layer Tc in a burn-in testconducted under a high temperature and high humidity condition, so thatthe intruding moisture is influenced by an electric field, and thecorrosion COR is induced. Here, another gap GA between the conductivelayer Tc and the edge of the fifth layer L22 occurs at the edge Tb2 asis the case with the edge Tb1.

It has become clear that the gaps GA between the conductive layer Tc andthe edge of the fifth layer L22 are formed at the time of developing theinsulating film 15 in such a way that the insulating film 15 isgradually removed by a developing solution, the developing solutionreaches the fifth layer L22, and the edges of the fifth layer L22 isetched and bored by the developing solution.

(Configuration 1 of Terminal Portion According to Embodiment)

Next, a configuration example of a terminal portion according to theembodiment will be explained with reference to FIG. 13 to FIG. 17 .

FIG. 13 is a plan view showing the configuration example of the terminalportion T1 according to the embodiment. FIG. 14 is a cross-sectionalview of the terminal portion T1 taken along the line G-G′ shown in FIG.13 . FIG. 15 is a cross-sectional view of the terminal portion T1 takenalong the line H-H′ shown in FIG. 13 . FIG. 16 is a cross-sectional viewof the terminal portion T1 taken along the line I-I′ shown in FIG. 13 .FIG. 17 is an enlarged view conceptually showing the terminal portion T1shown in FIG. 13 and the conductive beads CP in the anisotropicconductive film ACF. Here, in FIG. 14 , lateral dimensions are differentfrom real dimensions and the lateral dimensions are depictedcontractively. Furthermore, the insulating film 12, the insulating film11, and the insulating substrate 10 in the first substrate SUB1 are notdepicted in FIG. 15 and FIG. 16 .

As shown in FIG. 13 , the outer shape of the terminal portion T1 is arectangle having a pair of long sides Y11 and Y12 and a pair of shortsides X11 and X12. The peripheral portions of the terminal portion T1along the pair of long sides Y11 and Y12 of the terminal portion T1 arecovered by a pair of insulating films 15.

As shown in FIG. 14 , the terminal portion T1 includes: a conductivelayer Ta; a conductive layer Tb; a conductive layer Tc; and a conductivelayer Td. Here, the insulating film 14 is not disposed in an area wherethe terminal portion T is disposed in the first substrate SUB1.Therefore, the insulating film 16 is laminated on the insulating film13. In FIGS. 14 , y11 and y12 illustratively show the positions of thelong sides Y11 and Y12 respectively. In this example, the position y11shows the vicinity of the edge of the left peripheral portion VTb1 ofthe conductive layer Tb, and the position y12 shows the vicinity of theedge of the right peripheral portion VTb2 of the conductive layer Tb. Inother words, the peripheral portions VTb1 and VTb2 of the conductivelayer Tb are areas corresponding to the long sides Y11 and Y12respectively.

The conductive layer (first metal portion) Ta is located on theinsulating film 13. The conductive layer Ta is formed of the secondmetal layer, located in the same layer as the signal line S6, and formedof the same material as the signal line S6. The conductive layer Tb isformed of a laminated film formed by laminating titanium, aluminum, andtitanium in this order.

The conductive layer (second metal portion) Tb is formed of the thirdmetal layer and laminated on the conductive layer Ta and the insulatingfilm 13, and covers the whole surface (that is, the whole upper surfaceand the whole side surface) of the conductive layer Ta. The conductivelayer Tb and the insulating film 13 are covered by the insulating film(organic insulating film) 15. The peripheral portions VTb1 and VTb2 ofthe conductive layer Tb along the long sides Y11 and Y12 including theside surfaces of the peripheral portions VTb1 and VTb2 of the conductivelayer Tb are covered by the insulating film 15. On the peripheralportions of the conductive layer Ta along the long sides Y11 and Y12,the conductive layer Ta, the conductive layer Tb, and the insulatingfilm 15 are laminated in this order. The insulating film 15 includes athrough bore (a first through hole or a first opening) CH41 thatpenetrates to the conductive layer Tb. The insides of the peripheralportions VTb1 and VTb2 of the conductive layer Tb are exposed via thethrough bore CH41 made in the insulating film 15. The film thickness ofthe insulating film 15 is set to be, for example, approximately 1.5 μm.The conductive layer Tb is located in the same layer as the metal wiringML6 shown in FIG. 5 and formed by the same material as the metal wiringML6. In other words, the conductive layer Tb is formed of a laminatedfilm formed by laminating molybdic, aluminum, and molybdic in thisorder.

The conductive layer (first transparent conductive film) Tc is laminatedon the conductive layer Tb and the insulating film 13 and covers theconductive layer Tb. The conductive layer Tc is in contact with theconductive layer Tb at a position where the through bore CH41 is formedin the insulating film 15. In addition, the conductive layer Tc is incontact with the insulating film 15 at positions where the conductivelayer Tc overlaps the peripheral portions VTb1 and VTb2 of theconductive layer Tb. The conductive layer Tc and the insulating film 13are covered by the insulating film (inorganic insulating film) 16. Inother words, the insulating film 16 covers the conductive layer Tc atpositions where the insulating film 16 overlaps the peripheral portionsVTb1 and VTb2 of the conductive layer Tb and includes a through bore (asecond through hole or a second opening) CH42 that exposes theconductive layer Tc at a position where the through bore CH41 in theinsulating film 15 is formed. The conductive layer Tc is located in thesame layer as the common electrode CE shown in FIG. 5 and formed of thesame material as the common electrode CE.

The conductive layer (second transparent conductive film) Td is locatedon the insulating film 16 and laminated on the conductive layer Tcexposed via the through bore CH42 formed in the insulating film 16. Inother words, the conductive layer Td is in contact with the insulatingfilm 16 at positions where the conductive layer Td overlaps theperipheral portions VTb1 and VTb2 of the conductive layer Tb and is incontact with the conductive layer Tc at a position where the throughbore Ch42 is formed in the insulating film 16. The conductive layer Tdis located in the same layer as the pixel electrode PE11 shown in FIG. 6and formed of the same material as the pixel electrode PE11.

The depth of the through bore CH41 is the same as the thickness of theinsulating film 15 and, for example, approximately 1.5 μm. If it isassumed that each of the diameters of the conductive beads CP in theanisotropic conductive film ACF is, for example, approximately 3.8 μm,each of the diameters of the conductive beads CP is set to be smaller orshallower than the depth of the through bore CH41 in the insulating film15 as shown in FIG. 14 .

As mentioned above, because the right peripheral portion VTb1 and theleft peripheral portion VTb2 of the conductive layer Tb are covered bythe pair of the insulating films 15, the bore or gap of the aluminum ofthe laminated film composing the conductive layer Tb, which has beendescribed in the case of the comparative example, can be prevented fromoccurring. Therefore, the insulating film 16 can sufficiently cover theconductive layer Tc. As a result, even the burn-in test is conducted inthe high temperature and high humidity condition, moisture can beprevented from intruding between the insulating film 16 and theconductive layer Tc, and therefore corrosion at the peripheral portionscorresponding to the pair of the long sides Y11 and Y12 of the terminalportion T1 is prevented from being induced. With this, the improvementof the reliability of the terminal portion T1 can be attained.

FIG. 15 shows a cross-sectional view of the terminal portion T1 takenalong the line H-H′ shown in FIG. 13 , and x11 illustratively shows theposition of the short side X11 of the terminal portion T1. In thisexample, the position x11 shows the vicinity of the left peripheralportion of the conductive layer Tb. As shown in FIG. 15 , the insulatingfilm 15 is not formed between the conductive layer Tb and the conductivelayer Tc at the left peripheral portion of the conductive layer Tbunlike in the case of the configuration shown in FIG. 14 . Therefore,the conductive layer Tb and the conductive layer Tc can be laminated.Because other portions shown in FIG. 15 are the same as shown in FIG. 4, explanations thereof will be omitted.

FIG. 16 shows a cross-sectional view of the terminal portion T1 takenalong the line I-I′ shown in FIG. 13 , and x12 illustratively shows theposition of the short side X12 of the terminal portion T1. The rightside of the position x12 composes the wiring portion W. At the rightperipheral portion of the conductive layer Tc, the insulating film 15 isnot formed between the conductive layer Tb and the conductive layer Tcunlike in the case of the configuration shown in FIG. 14 . Theconductive layer Ta and the conductive layer Tb extend to the right sidewithout both conductive layers Ta and Tb being cut to compose the wiringportion W. In the vicinity of the left side of the position x12, theinsulating film 16 is formed between the right peripheral portion of theconductive layer Tc and the right peripheral portion of the conductivelayer Td. Furthermore, the insulating film 16 is laminated on theconductive layer Tc so as to cover the upper surface of the conductivelayer Tc.

In FIG. 17 , enlarged views of two terminal portions T1 and ananisotropic conductive film ACF overlapped by the two terminal portionsT1 are depicted. The anisotropic conductive film ACF shows aconfiguration of an anisotropic conductive film including pluralconductive beads CP arranged in plural lines as one of configurationexamples. As mentioned above, the diameter Dcp of a conductive bead inthe anisotropic conductive film ACF is, for example, 3.8 μm, and thedepth of the through bore CH41 in the insulating film 15 is, forexample, 1.5 μm. In addition, the length of the short side X11 of aterminal portions T1 is, for example, 16.7 μm. As described in FIG. 14 ,conductions between the conductive beads CP in the anisotropicconductive film ACF and the terminal portion T1 at the through bore CH41in the insulating film 15 can securely be obtained. Furthermore, asshown in FIG. 17 , if the anisotropic conductive film ACF including theconductive beads CP arranged in the plural lines is used, electricconductions between the conductive beads CP and the terminal portions T1can be obtained in a securer manner. The conductive beads CP can befixed or disposed in the through bore CH41 more securely in this casethan in the case of the flat terminal portion T11 shown in FIG. 11 . Inother words, in the terminal portion T11 shown in FIG. 11 , electricconductions between conductive beads CP and the terminal portion T11 areobtained via the through bore or concave portion almost composed of thestep of the thickness of the insulating film 16. On the other hand, inthe terminal portion T1 shown in FIG. 14 , the depth of a unifiedthrough bore or concave portion composed of the through bore CH41 in theinsulating film 15 and the through bore CH42 in the insulating film 16is deeper than the depth of the through bore or concave portion in theterminal portion T11 shown in FIG. 11 by the depth of the through boreCH41 in the insulating film 15. Therefore, the conductive beads CP canbe fixed or disposed in the unified through bore or concave portion moresecurely in the terminal portion T1 shown in FIG. 14 than in theterminal portion T11 shown in FIG. 11 , so that better electricconductions can be obtained.

(Configuration 2 of Terminal Portion According to Embodiment)

FIG. 18 is a plan view of a terminal portion T3 according to theembodiment. As described in FIG. 8 , the terminal portion T3 has anapproximately U-shaped outer shape, and for example, the terminalportion T3 can be used as a terminal to which electric power issupplied. Although the terminal portion T3 has the approximatelyU-shaped outer shape, as explained in FIG. 13 , the shape of theterminal portion T3 can be considered to be a rectangle having a pair oflong sides Y11 and T12 and a pair of short sides X11 and X12. Therefore,it will be all right if a pair of insulating films 15 is formed at theperipheral portions of the terminal portion T3 along the long sides Y11and Y12 of the terminal portion T3 as explained in FIG. 13 . In otherwords, in the burn-in test under the high temperature and high humidityenvironment, the peripheral portions of the terminal portion T3 alongthe pair of the long sides Y11 and Y12 are areas to which attentionshould be paid regarding the relations with terminal portions disposedadjacently to the left side and the right side of the terminal portionT3. Therefore, forming the pair of insulating films 15 at the peripheralportions of the terminal portions T3 along the pair of the long sidesY11 and Y12 of the terminal portion T3 makes it possible to improve thereliability of the approximately U-shaped terminal portion T3.

Although the above description is made about the approximately U-shapedterminal portion T3, in the case where an approximately E-type terminalportion or a comb-type terminal portion is present in the mounting unitMA, a technological idea similar to the above can also be applied to theapproximately E-type terminal portion or the comb-type terminal portion.

Here, as for the terminal portion T2 that is explained in FIG. 8 and setto be electrically floating, whether or not a pair of insulating film 15is formed along a pair of the long sides of the terminal portion T2 doesnot make any difference. This is because it is considered that therewill be no special trouble with a burn-in test of the terminal portionT2 under a high temperature and high humidity environment owing to thefact that the terminal portion T2 is electrically floating.

It is also possible that the insulating film 15 is formed along the longside Y11 or Y12 of one terminal portion having a higher potential of twoterminal portions that are adjacent to each other and between which alateral electric field is induced in the burn-in test under the hightemperature and high humidity environment.

MODIFICATION EXAMPLES

Hereinafter some modification examples will be explained.

Modification Example 1

FIG. 19 is a plan view of a terminal portion T1 according to amodification example 1. FIG. 20 is a cross-sectional view of theterminal portion T1 taken along the line J-J′ shown in FIG. 19 . Thetermination portion T1 shown in FIG. 19 is different from thetermination portion T1 shown in FIG. 13 in that an insulating film 15 isformed at the peripheral portion of the terminal portion T1 along theshort side X11 of the terminal portion T1 shown in FIG. 19 . In otherword, in FIG. 19 , an approximately U-shaped insulating film 15 isformed at the peripheral portion of the terminal portion T1 along a pairof the long sides Y11 and Y12 and the short side X11 of the terminalportion T1.

As shown in FIG. 20 , in a cross-sectional view of the terminal portionT1 taken along the line J-J′ shown in FIG. 19 , the insulating film 15is formed so as to cover the peripheral portion of a conductive layer Tbsimilarly to the explanation made in FIG. 14 . The constitution of thecross-sectional view of the terminal portion T1 taken along the lineJ-J′ is the same as the constitution of the cross-sectional view shownin FIG. 14 , and therefore redundant explanation thereof will beomitted.

Modification Example 2

FIG. 21 is a plan view of a terminal portion T1 according to amodification example 2. FIG. 22 is a cross-sectional view of theterminal portion T1 taken along the line K-K′ shown in FIG. 21 . Thetermination portion T1 shown in FIG. 21 is different from thetermination portion T1 shown in FIG. 13 in that plural rectangle-shapedinsulating film 16 a are formed between a pair of the long sides Y11 andY12 of the terminal portion T1 shown in FIG. 21 in a planar view. Inother word, the plural insulating films 16 a are formed between aconductive layer Tc and a conductive layer Td in an area where theconductive layer Tb and a conductive layer Tc are in contact with eachother as shown in FIG. 22 .

By forming the plural insulating films 16 a on the conductive layer Tcin the area where the conductive layer Tb and a conductive layer Tc arein contact with each other, the surface of the conductive layer Td inthe area where the conductive layer Tb and a conductive layer Tc are incontact with each other includes plural step portions owing an influenceexerted by the film thicknesses of the plural insulating films 16 a. Theplural steps formed on the surface of the conductive layer Td play arole of improving electric connections between the conductive beads CPin an anisotropic conductive film ACF and the conductive layer Td of theterminal portion T1.

Although four insulating films 16 a are depicted in FIG. 22 as aconfiguration example, it is all right if there is one insulating film16 a or more. In addition, although it is described that the shapes ofthe plural insulating films 16 a in a planar view in FIG. 21 arerectangular, the shapes of the plural insulating films 16 a are notlimited to rectangles. The shapes of the insulating films 16 a in aplanar view can be changed to circles, rectangles, ovals or combinationsthereof. In other words, it is all right if steps are formed in thesurface of the conductive layer Td. The number, the planar shapes, andthe like of the insulating films 16 a can be modified variously under aprerequisite that an electric connection between the conductive layer Tcand the conductive layer Td is securely attained.

The plural insulating films 16 a can be formed by selectively patterningthe insulating film 16. For example, the plural insulating films 16 acan be formed in parallel in a process in which a through bore CH42 isformed in an insulating film 16. This process makes it possible to formthe plural insulating films 16 a without increasing the relevantmanufacturing cost. Although the description to the effect that theplural insulating films 16 a are formed using the insulating film 16 hasbeen made so far, a method for forming the plural insulating films 16 ais not limited to this method. It is also conceivable that the pluralinsulating films 16 a are formed using an insulating film other than theinsulating film 16.

Furthermore, the mounting area MA can be perceived as a terminal areaMA, and although the terminal portion T connecting to the flexiblewiring substrate 1 has been explained in detail in this example, if theterminal portion T and a driver IC are configured in such a way that theterminal portion T is formed in the mounting area MA and the driver ICis connected to the first substrate SUB, the terminal portion T may beused for connecting to the driver IC.

In addition, the structure of the terminal portion T is made in such away that the terminal portion T can be not only used for connecting tothe flexible wiring substrate 1 but also used as an inspection pad andthe like, for example.

Furthermore, the organic insulating film 15 of the terminal area MA iscorresponding to the organic insulating film 15 of the display portionDA, and the pattering of the organic insulating film 15 of the terminalarea MA is executed at the same time as the patterning of the organicinsulating film 15 of the display portion DA. In other words, theorganic insulating film 15 of the terminal area MA is removed except forthe peripheral portion of the conductive layer Tb (the third metalportion).

In addition, the insulating film 15 can be formed of not only an organicmaterial but also an inorganic material. In the case where theinsulating film 15 is formed of an inorganic material, it is preferablethat the thickness of the insulating film 15 is as large (thick) aspossible when flatness between the insulating film 15 and the thirdmetal wiring is taken into consideration. However, it is difficult toform an inorganic insulating film having its film thickness almost equalto the film thickness of an organic insulating film (to form the filmthickness of the inorganic insulating film equivalent to the filmthickness of the organic insulating film). Therefore, if the insulatingfilm 15 is formed of an inorganic material, it is conceivable that theinsulating film 15 is formed of plural layers each of which is composedof an inorganic film.

As described above, a display device capable of attaining theimprovement of the reliability of the terminal portion can be providedaccording to the embodiment.

It is conceivable that all display devices that can be implemented bythose skilled in the art through appropriate design modifications on thebasis of the above-described display device according to the embodimentof the present invention fall within the scope of the present inventionas long as those display devices include the gist of the presentinvention.

It should be understood that, if various alternation examples andmodification examples are easily conceived by those skilled in the artwithin the idea of the present invention, those alternation examples andmodification examples also fall within the scope of the presentinvention. For example, devices obtained in the case where those skilledin the art appropriately add components to the above-describedembodiment, delete components from the above-described embodiment, addprocesses to original processes for the above-described embodiment, omitprocesses from the original processes, or alter conditions forimplementing the above-described embodiment fall within the scope of thepresent invention as long as the devices do not deviate from the gist ofthe present invention.

In addition, it should be obviously understood that other operationaleffects, which are brought about by this embodiment, clear from thedescriptions of the present specification, and can be accordinglyconceived by those skilled in the art, are brought about by the presentinvention.

Various inventions can be achieved by appropriately combining pluralcomponents disclosed in the above-described embodiment. For example, anew invention will be achieved by deleting some components from all thecomponents included in the embodiment. Alternatively, another newinvention will be achieved by appropriately combining components fromthe above-described embodiment and modifications 1 and 2.

What is claimed is:
 1. A display device comprising: a first substrateincluding plural pixels in a display portion and a terminal portionoutside of the display portion; and a flexible printed circuit substrateconnected to the terminal portion, wherein the first substrate includes:an insulating substrate; a first insulating film; a second insulatingfilm on the first insulating film; a third insulating film on the secondinsulating film; a fourth insulating film on the third insulating film;a video signal line formed of a second metal layer between the firstinsulating film and the second insulating film in the display portion; ametal wiring formed of a third metal layer between the second insulatingfilm and the third insulating film in the display portion; a firsttransparent electrode formed of a first transparent conductive filmbetween the third insulating film and the fourth insulating film in thedisplay portion; and a second transparent electrode formed of a secondtransparent conductive film on t fourth insulating film in the displayportion, wherein the terminal portion includes a first metal portionformed of the third metal layer, a peripheral portion of the first metalportion is covered by a third insulating film, and the inside of theperipheral portion of the first metal portion is exposed via a firstthrough hole formed in the third insulating film.
 2. The display deviceaccording to claim 1, wherein the first metal portion formed of thethird metal layer is a laminated structure with three metal layer. 3.The display device according to claim 1, wherein the third insulatingfilm covering the peripheral portion of the first metal portion is aninorganic insulating film.
 4. The display device according to claim 1,wherein the third insulating film covering the peripheral portion of thefirst metal portion is an organic insulating film.
 5. The display deviceaccording to claim 1, wherein the first metal portion formed of thethird metal layer is a different material form a material the firstmetal layer.
 6. The display device according to claim 1, wherein thefirst metal portion formed of the third metal layer is a differentmaterial form a material of the second metal layer.
 7. The displaydevice according to claim 5, wherein the first metal portion formed ofthe third metal layer is a different material form a material of thesecond metal layer.
 8. The display device according to claim 1, whereina thickness of the first metal portion formed of the third metal layeris thinner than a thickness of the video signal line formed of thesecond metal layer.
 9. The display device according to claim 1, whereinin the display portion, the first transparent electrode has pluralsensor electrodes arranged in a matrix, and in the display portion, themetal wiring is connected to one of the plural sensor electrodes via asecond through hole formed in the third insulating film.
 10. The displaydevice according to claim 1, wherein a wiring is pulled out from thefirst metal portion of the terminal portion to the display portion, andthe wiring is formed of the third metal layer.
 11. The display deviceaccording to claim 1, wherein a wiring is pulled out from the firstmetal portion of the terminal portion to the display portion, and thewiring is formed of the second metal layer.
 12. The display deviceaccording to claim 1, wherein a wiring is pulled out from the firstmetal portion of the terminal portion to the display portion, and thewiring has a laminated structure of the second metal layer and the thirdmetal layer.
 13. The display device according to claim 1, wherein theterminal portion further includes a first conductive layer formed of thefirst transparent conductive layer, the first conductive layer is incontact with the first metal portion at a position where the firstthrough hole, and the first conductive layer is in contact with thethird insulating film at a position where the first conductive layeroverlaps the peripheral portion of the first metal portion.
 14. Thedisplay device according to claim 1, wherein the terminal portionfurther includes a first conductive layer formed of the secondtransparent conductive layer, the first conductive layer is connected tothe first metal portion in the first through hole, and the firstconductive layer covers the third insulating film at a position wherethe first conductive layer overlaps the peripheral portion of the firstmetal portion.
 15. The display device according to claim 1, wherein theperipheral portion of the first metal portion is in contact with thefirst insulating film.